fix(css): single hyphen shouldn't be treated as css identifier

[lbwa]

close #1308

CSS spec

In CSS Selector level 4:

Attribute values must be <ident-token>s or <string-token>

According to <ident-token> rules, single hyphen - without quotes is not valid ident-token which means "-" shouldn't be unwrapped as -. On the other hand, "-" is a valid <string-token> and a valid part of CSS attribute selector.

Extra helpful informations about CSS escape in w3c

cc @evanw

[evanw]

Thanks for the fix! Looks like the underlying reason is that utf8.DecodeRuneInString treats the end of the string as the U+FFFD replacement character which is being interpreted here as a non-ASCII code point in the "name-start code point" rule. I'll fix that part myself.

[lbwa]

Thanks for the fix! Looks like the underlying reason is that utf8.DecodeRuneInString treats the end of the string as the U+FFFD replacement character which is being interpreted here as a non-ASCII code point in the "name-start code point" rule. I'll fix that part myself.

Thanks for your explanation